Shown below are statistical MJO index forecast products. Three statistical MJO forecasts are shown and all involve application
of the Wheeler and Hendon (2004) methodology to historical data. Statistical models include: (1) Constructed Analogue (Van den dool et al. (1994; 1995; 2003; 2007)),
lagged linear regression (Wheeler and Hendon (2004), Jones et al. (2004), Seo et al. (2008), among others), and a simple autoregressive model (simplified form from Jones et al. 2004). More details of the production of these forecasts here at CPC can be provided if necessary. The first figure is a phase diagram illustrating the 15 day forecast for all three methods. The remaining two figures are based on the constructed analogue forecast only.

Statistical Models Phase Diagram

Phase diagram showing the evolution of the last 40 days of observations along with the 15 day forecasts from the constructed analogue (green), autoregressive model (AR), and lagged linear regression (red). The thick (thin) lines represent the statistical model forecasts for the first 7 days (last 8 days) respectively.

Constructed Analogue -- Spatial OLR Anomalies

Forecasts of MJO associated anomalous OLR for the next 15 days from the constructed analogue forecasts based of forecasts of RMM1 and RMM2. Blue (yellow/red) shades show negative (positive) OLR anomalies and enhanced (suppressed) convection. Forecasts do not include direct contributions from other climate modes such as ENSO, monsoons, etc. - only the MJO.

Constructed Analogue -- Time-Longitude OLR Anomalies

Time-longitude section (7.5N-7.5S) of MJO associated anomalous OLR for the last 180 days and for the next 15 days from the constructed analogue forecast based on RMM1 and RMM2. Blue (yellow/red) shades show negative (positive) OLR anomalies and enhanced (suppressed) convection. Forecasts do not include direct contributions from other climate modes such as ENSO, monsoons, etc. - only the MJO.